Bismethylenedioxy steroids and methods of making same



BISMETHYLENEDIOXY STEROIDS AND METHODS OF MAKING SAME Roger E. Beyler,Westfield, and Lewis H. Sarett, Princeton, N.J., assignors to Merck &Co., Inc., Rahway, NJ., a corporation of New Jersey No Drawing.Application August 18, 1958 Serial No. 755,403

31 Claims. (Cl. 260-23955) This invention relates generally to newcompounds derived from steroids which have attached to the condensedring nucleus a dihydroxyacetone side chain. More particularly it isconcerned with new steriods in which a dihydroxyacetone side chain of apregnane or unsaturated pregnane is deactivated by formation of abismethylenedioxy derivative. It is further concerned with a method formaking such new compounds from steriods having a free or esterifieddihydroxyacetone side chain.

This application is a continuation-in-part of our copending applicationSerial No. 632,010, filed January 2, 1957, now abandoned. v

It is well known that the vast majority of physiologically-activesteroids are members of the pregnane series having a free or esterifieddihydroxyacetone side chain at the C-17 position. This side chain issubject to oxidation at -21, to reduction at 0-20, to rearrangementleading to a D-homo steroid and to decomposition under strongly acidicor basic conditions. Since such reactions and reaction conditions areoften necessary to modify or introduce functional substituents in thenucleus of the steroid molecule, the ability to deactivate or block thedihydroxyacetone side chain is important for the practical synthesis ofphysiologically-active steroids. Some success has been achieved byforming C-ZO ethylenedioxy steroids but this blocking group is notcompletely satisfactory since it is quite acid labile and serves todeactivate only one portion of the dihydroxyacetone side chain, theketone function.

It is an object of our invention to provide a new series of steroidcompounds in which the dihydroxyacetone side chain of a pregnane orunsaturated pregnane is deactivated by a very stable group wherein allthree of the carbon atoms in the dihydroxyacetone chain are protected.It is a further object to protect the side chain of17a,21-dihydroxy-20-keto pregnanes and unsaturated derivatives thereofwith a group that can be conveniently removed to regenerate thedihydroxyacetone moiety. A more specific object is to provide newderivatives of steroids'having a dihydroxyacetone side chain in whichthis functional moiety is protected by a bismethylenedioxy group. Anadditional object is a process for making this new type of steroid froma steroidv having the dihydroxyacetone side chain. Other and furtherobjects will become evident from the detailed explanation of ourinvention hereinbelow.

.We have found that when a steroid having a dihydroxyacetone side chainattached to the condensed ring steriod nucleus is treated withformaldehyde in the presence of a strong acid there is obtained abismethylenedioxy steroid in which all three carbon atoms of thedihydroxyacetone moiety are a part of at least one of the five-memberedrings thus formed. We have also found that the presence of nuclearsubstituents or nuclear double bonds do not interfere with or preventthe formation of such bismethylenedioxy compounds. Thus, when thedihydroxyacetone moiety is at the 0-17 position of the nucleus, acompound is obtained having at carbons l' l, 20 and 21 the structureo-on, 21 EUR l The new process may then be pictured structurally asapplied to a steroid of the pregnane series having a dihydroxyacetoneside chain at C-17 as follows:

O-CH:

Bythe dihydroxyacetone side chain is meant the'17ahydroxy-20-keto-21-hydroxy moiety of a steroid such asI. We refer tosuch new steroids as 17-20,2021 bismethyl enedioxy steroids. Althoughthe dihydroxyacetone moiety must be unsubstituted in order to react asshown above, the steroid actually charged to the reaction mixture may,if desired for convenience sake, be esterified at either or both of thehydroxy groups since' such ester groups are hydrolyzed under thereaction conditions.

It will be evident that a dihydroxyacetone side chain located atpositions of the steroid condensed ring nucleus other than at C-17, e.g.atC-16, at C-17a in D-homo steroids, and at other positions in thenucleus may also be converted by treatment with formaldehyde under ourreaction conditions to the corresponding bismethylene dioxy compounds.However, since the physiologicallyactive steriods known at the presenttime have this function at C-17, we will discuss primarily thosecompounds, which may be described as l7a,2l-dihydroxy 20-keto' steroidsof the pregnane series.

17-20,20-2l bismethylenedioxy steroids of the pregnane series areprepared by treating a 17a,21-dihydroxy?20-' keto steroid of thepre'gnane series with formaldehyde in the presence of a strong acid. Anexcess of formaldehyde is employed in order to obtain the optimum yieldof bis-dioxy compound.

In making a 17-20,20-2l bismethylenedioxy steroid we are able to usepure formaldehyde itself, the readily available 40% aqueous formaldehydesolution (forma-, lin) or other compounds which act as a source offormal-' dehyde in the reaction mixture. Paraformaldehyde, for-' mal andtrioxane are examples of compounds which act as a source offormaldehyde.

The reaction is carried out in the presence of a strong acid, such ashydrochloric, perchloric, hydrobromic, sul-' furic, phosphoric and likeacids. log k of less than 2.25 are considered strong acids for ourprocess and any of these may be employed. The -log k of a large numberof organic and inorganic acids appear in Langes Handbook of Chemistry,Handbook Publishers, Inc., 8th ed., 1952, pp. 1229-1233. This andsimilar tables in other texts provide ready informa tion as to the log kvalues of different acids so that acids suitablefor usein our inventionmay be determined readily. Lewis acids or formic acid may also be used;as the acid catalyst in preparing 17-20,20-2l bismethyb Acids which have"a assess? enedioxy'steroids' although the log k of formic acid is 3;75.

The reaction of a 17a,2 l-dihydroxy-20-keto steroid with formaldehyde iscarried out in an organic solvent inertunder the reaction conditions.This may be a water-miscible solvent such as dioxane or tetrahydrofuranin which case the reaction takes place in a one-phase solvent system.Alternatively, and preferably formation of the 17-20,20-21bismethylenedioxy steroid is effected in a two-phase reaction mixturewherein the steroid is dissolved in a water-immiscible organic solventand the second phase is the aqueous acid-formaldehyde phase. Such anaqueouszorganic solvent two-phase reaction mixture is very satisfactoryand is preferred for optimum yields under our operating conditions.- It.is desirable that both the starting material and the reactionproduct besoluble in the organic solvent, but satisfactory yields and quality of17-20,20-21 bismethylenedioxy steroids are obtained when the end productis soluble and the starting 17,21- dihydroxy-20aketo-steroid isinsoluble in the organic solvent. Suitable water-immiscible organicsolvents for our process are chloroform, methylene chloride, ethylenedichloride, carbon tetrachloride, ethylene dibromide, methylene bromide,benzene, ethyl ether and the like, the chlorinated solvents being mostsatisfactory.

Formation of our new l7-20,20-2l bismethylenedioxy steroids of thepregnane series is ordinarily conducted at temperatures from about 30 C.to about +50 C. For ease of operation temperature of C. to about +35 C.are preferred and satisfactory yields are realized at such temperatureswith most steroids.

' The time required for obtaining optimum. yields of l7-20,202lbismethylenedioxy steroids will depend to some extent on the particularreaction temperatureutilized. We have also found that the reaction timenec essary for good yields is a function of the type of. 1711,21.-dihydroxy-ZO-keto steroid employed as starting material. For instance,in a chloroform-formalin-hydrochloric acid reaction system, about 40-50hours. are required for optimumconversion of cortisone to 17-20,20-2lbismeths ylenedioXy-4-pregnene-3,1l-dione, whereas only l530.

minutes are needed to convert prednisolone in high yield to l7-20,20-21bismethylenedioxy-l,4-pregnadiene-11 8-01- 3-one.

This difference in steroid reactivity does not, however, present anyserious difiiculty in readily determining the proper length of time torun the reaction under. any desired process condition. The course ofconversionof the 171:,2l-dihydroxy-2o keto moiety of a steroid of thepregnane series to a l7-20,20-21 bismethylenedioxy derivative is readilyfollowed. by use of the diam'sole hisdiphenyltetrazolium chloridereagent, commonly known as the B.T. reagent. This reagent reacts with adihydroxyacetone grouping of a steroid to give a. deep blue solution. Itdoes not form a blue color with the 17- 20,20-21 bismethylenedioxysteroids. By means of this B.T. test, therefore, the degree of reactioncan be followed quantitatively, or if desired only semi-quantitative-1y, since the intensity of the blue color is a function of the amount of170:,21-dihYdI'0XY-20-k8t0 steroid present in the solution tested. Thisintensity of color can conveniently be measured against a known standardsolution and the extent of reaction easily calculated. Use of the BlueTetrazolium (B.T.) reagent in assaying for the presence of adihydroxyacetone moiety is described more fully in a publication byMader et al., Anal. Chem. 24, 666 (1952).

By the process discussed above, and where necessary following the courseof reaction by the B.T. test, any 170:,21-dihYd1'OXY-20-k6t0 steroid ofthe pregnane series" may be converted to a 17-20,20.-21bismethylenedioxy steroid.

Functional groups. or substituents in other parts of the pregnanemolecule do not interfere with formation of the bismethylenedioxy sidechain and in most cases are not themselves destroyed or modified underthe reaction. conditions: Since strong" acid is present during thereaction, any unusually acid-sensitive substituents in other portions ofthe molecule might possibly react and we pre fer, where such sidereactions are undesired and apt to occur, to temporarily form,iffeasible, an acid stable derivative of such substituents. In the caseof ll-hydroxylated steroids, reactionat the ll-position may besubstantially eliminated by carrying out our process in asolventisystern essentially free. of. alcohols, particularly the loweralkanols; Thus, in an alcohol free system, bydrocortisone andprednisolone are readily converted by treatment with formaldehyde andstrong acid to 17- 20,20-21 bismethylenedioxy-4-pregnene-11/3-ol-3-oneand 17-20,20-21 bismethylenediox -l,4-pregnadiene--01-3- onerespectively. If alcohol should be present the l7- 20,20-21bismethylenedioxy derivative, of course, forms but an alkoxymethyl etherderivative of the ll-hydroxy groupvis' also formed; Thisis, however,cleavedduring. removal of the bismethylenedioxy function.

Where functional substituents. in other parts of. the molecule, such asamines, are those that normally react with aldehydes, they willreactduring ourv process. This is not a serious difiiculty since in mostinstances-the original functional group can be regenerated readily.

We are able, therefore, to carry. out our new process on steroids of thepregnane series generally. Ordinarily, the steroid reactants will besubstituted at the 3-position with an oxygen-containing function or afunction reconvertible by hydrolysis to an oxygenated group, such as aketo or hydroxy group, or an ethylenedioxy, enamine, enol ether,

or ester moiety. The steroids may also have substituents such ashydroxy, keto, halo, ether or lower. alkyl groups-at.

other positions of the condensed ring nucleus; as for in stance atpositions 1, 2,, 3, 4, 6, 7, 9, 11, 12, 14, 15 0111 6.

A preferred group of 17-20,20-2l bismethylenedioxy steroids of theinvention have oxygenated functions at both;

the 3 and 11 positions of the condensedringsystem- Also: included withinthe preferred embodiments of the inverts tion are thosebismethylenedioxy steroids having aihalogen group, such as chloro, bromoor fluoro, at the 9.-posi'-- tion of the ring. Our new compounds may becompletely saturated or have one or more double bonds attached,forexample, to carbon. atoms 1, 4, 5, 6, 7, 11 or 14. For

example, there may be double bonds in the 1:2, 4:5, 5:6,. Some' 8:9,9:11 and at other positions of the molecule. representative examples ofnew steroids made by the method of our inventionfromthe. corresponding.17,21- dihydroxy-ZO-keto steroids. are- The desired products areisolated from the reaction mixture by extraction into an organic solventfollowed by a chromatographic separation or by recrystallization from asuitable solvent. Certain of the 3,1l-bisoxygenated-17- 20,20-21bismethylenedioxy ring A unsaturated steroids of the pregnane serieshave cortisone-like activity and may themselves be used in the treatmentof diseases which respond to anti-inflammatory agents. For the mostpart, however, the greatest value of our new compounds lies in the factthat they represent intermediates in which the important C-17dihydroxyacetone side chain is rendered chemically inert andinaccessible so that reactions and transformations which would destroyan unprotected dihydroxyacetone moiety may be used safely on otherportions of the steroid molecule. For example, Claisen condensations atpositions alpha to a carbonyl group may be carried out withoutundesirable reaction in the side chain. In this way Z-methyl cortisoneor Z-methylhydrocortisone may be prepared from cortisone orhydrocortisone by first making the 17-20,20-21 bismethylenedioxyderivative, treating the resulting compound successively with methyloxalate and a methylating agent, and finally treating the 2methyl-l7-20,20-21 bismethyleizedioxy steroid with sulfuric acid toreverse the bismethylenedioxy function and obtain the Z-methyl cortisoneor hydrocortisone. This process would not be feasible with anunprotected dihydroxyacetone side chain since extensive side reactionwould occur at the 21-position.

Furthermore, after inactivation of the side chain by our method, it isnow possible to treat a 17a,21-diol-20-keto steroid of the pregnaneseries having a nuclear carbonyl or oxide function with a metal alkyl ormetal Grignard reagent thereby alkylating the nucleus without adversereactions in the side chain. These new compounds also provide aconvenient method for selectively reducing a carbonyl group in the Aring of the steroid nucleus without also reducing the ZO-ketosubstituent, and for selectively blocking, for any purpose, the 20-ketosubstituent of a 3,20-diketo steroid.

When the desired reactions have been performed on the steroid with theprotected dihydroxyacetone side chain, the side chain can be readilyregenerated by treatment of the l7-20,20-2l bismethylenedioxy compoundwith acid. This process of reforming the l7a,2l-dihydroxy-20-ketosteroid of the pregnane series is more fully described in our copendingapplication Serial No. 632,026, filed January 2, 1957.

The following examples are given for purposes of illustration and not byway of limitation:

EXAMPLE 1 .1 7-20,20-2I bismethylenedixy-4-pregnene-3,1I-di0ne 500 mg.of cortisone is suspended in 40 ml. of chloroform and 10 ml. of formalin(40% aqueous formaldehyde) and 10 ml. of concentrated hydrochloric acidare added. This two-phase system is stirred vigorously at roomtemperature for 52 hours. The aqueous phase is then made alkaline withaqueous sodium hydroxide, sepamelting point to 259262 C.

70. After re- 7 6 EXAMPLE 217-20,20-21-bismethylenedi0xy-4-pregnene-3,II-dione 500 mg. of cortisonefree alcohol is suspended in 2 5 ml. of chloroform. To this mixture isadded a solution of 10 ml. of concentrated hydrochloric acid and 10 ml.of formalin. The two-phase reaction mixture is stirred at roomtemperature for 19 hours, and at the end of this time, the chloroformlayer is separated. It is washed with a saturated solution of sodiumbicarbonate, dried and concentrated under vacuum to an amorphousresidue. Upon treament with boiling methanol, a crystalline productseparates weighing 328 mg. and having a melting point of 220-247 C.Further recrystallization from acetone-methylene chloride yieldssubstantially pure 17-20,20-21-bismethylenedioxy-4-pregnene-3, ll-dione.

The same product is obtained when a methylene chloride solution ofcortisone is heated with formalin and perchloric acid under theconditions described above.

, EXAMPLE 3 1 7-20,20-21-bismethylenedioxy-4-pregnene-3,1I-di0ne To asolution of 500 mg. of cortisone acetate in 25 ml. of chloroform isadded a mixture of 10 ml. of formalin and 10 ml. concentratedhydrochloric acid. This two-phase reaction mixture is stirred at roomtemperature for 70 hours. At the end of this time, the chloroform layeris separated and the inorganic layer extracted with chloroform. Thischloroform extract is added to the original chloroform layer and thesolution washed with dilute soduim bisulfate, then dried over magnesiumsulfate. The chloroform is removed under reduced pressure and anamorphous gum obtained, weighing 475 mg. After purification bychromatographing on acid washed alumina and elution with ether mg. of17-20,20-2lbismethylenedioxy-4-pregnene-3,ll-dione is obtained.

In like manner 4,9(l1)-pregnadien-17a,21-diol-3,20- dione is convertedto 17-20,20-21-bismethylenedioxy-4,9 1 1)-pregnadien-3-one, and4-pregnen-l7a,2l-diol-3,20- dione 21-acetate to17-20,20-21-bismethylenedioxy-4- pregnen-B-one.

EXAMPLE 4 1 7-20,20-21-bismethylenedioxy-4-pregnene-11fi-ol-3-0ne17-20,20-21-bismethylenedioxy-4-pregnene-3J1-dione To 500 mg. ofhydrocortisone suspended in 25 ml. of chloroform is added a mixture of10 ml. of formalin and 10 ml. of concentrated hydrochloric acid. Thetwophase reaction mixture is stirred at room temperature for a period of72 hours. At the end of this time, the layers are separated and theinorganic layer washed with chloroform. The combined chloroform extractsare washed with a saturated solution of sodium bicarbonate and thendried and concentrated under reduced pressure. The resulting gum ischromatogramed on acid washed alumina and washed alumina and anon-crystalline product obtained which is negative in the B.T. test andhas the infrared spectrum expected forl7-20,20-2l-bismethylenedioxy-4-pregnene-1 1 fl-ol-3-one.

This non-crystalline material is dissolved in 2 ml. of acetic acid andto this solution is added 60 mg. of chromium trioxide. The reactionmixture is allowed to stand at room temperature for ten minutes and atthe end of this time, 5 ml. of water added'to the mixture. The mix tureis extracted several times with methylene chloride, the methylenechloride extracts washed with dilute sodium bicarbonate, then dried andconcentrated to yield 17-20, 20-21-bismethylenedioxy-4-pregnene-3 11-dione.

EXAMPLE 5 v 17-20,20-21-bismethylenedi0xy-1,4-pregnadiene-3,I1- dione Toa suspension of 500 mg. of prednisone in .25 .ml. of chloroform is addeda mixture of 10 m1. of formalin .the original organic phase. I solutionis washed with a saturated solution of sodium hi- I washed alumina andeluted with ether. the ether gives the desired compound which, whencrystallized from methanol, has melting point 239-243 C. (dec.) I

and thetwo layers are then separated. The aqueous .layer is extractedonce with chloroform and the chloroform extract combined with theoriginal organic solvent layer.. The chloroform is Washed with asaturated solution of sodium bicarbonate, dried and concentrated underreduced pressure to a semi-crystalline solid Weighing 712 1mg. Thiscrude product is triturated with boiling .methanol and 352 mg. ofcrystalline material obtained,

melting point 175-195" C. After recrystallization of this material fromacetone and methanol, a pure sample of 17-20,20-2l-bismethylenedioxy 1,4pregnadiene 3,11-

dione, melting point 2l4-217 C., is obtained.

. The same product is obtained by using sulfuric acid in place ofhydrochloric acid.

EXAMPLE 6 Pr epara tibiiofi120,20-ZI-biSmethyIenediOxy-I,ipreghadiene-I1,B-bl-3-0ne-1I-methoxymethyletherTo a suspension of 500 mg. of prednisolone in 25 ml. of chloroform isadded a mixture of 10 ml. of formalin and 10 ml. of concentratedhydrochloric acid. This twophase system is stirred at room temperaturefor a period of 45 hours. At the end of this time, the two layers areseparated. The aqueous layer is extracted once with chloroform and thechloroform extract combined with The combined chloroform carbonate,,dried and concentrated under reduced pres- .sure to ,a semi-crystallinesolid weighing 500 mg. This product is recrystallized from methanol toyield 300 mg. .of product, melting at 191202 C. Recrystallization fromacetone and methanol gives a pure sample of 17-20,

20-21 -'bismethylene-dioxyl-l,4-pregnadiene 11,3 ol 3- one-llmethoxymethylether, melting point 217220 C.

is stirred in a nitrogen atmosphere for one-half hour. 2.5 ml. of a 2 Nmethanolic solution of sodium methoxide is .added and stirring continuedfor five minutes. 0.3 ml. of

water is then added and stirring continued for an additional fiveminutes, and the solutionthen acidified with acetic acid. The solvent isremoved under reduced pressure, the residue dissolved in chloroform andthe chloroform extracted in sequence with water, 10% sodiumbicarbonateand finally with water. The chloroform solution isdried oversodium sulfate and the solvent removed ,..under reduced pressure to give1.09 grams of crude 4,6-

pregnadien-17m,21-diol-3 ,11,20-trione.

A mixture of this diol, 50 ml. of chloroform, 20 ml. of concentratedhydrochloric acid and 20 ml. of formalin .is stirred vigorously at roomtemperature for 64 hours.

50 ml. of chloroform and 50 ml. of water are then added,

I the layers separated, and the organic phase washed in se- .quence withwater, 10% sodium bicarbonate and again with water. After drying withsodium sulfate, the chloroform is removed under reduced pressure to givea residue of 17 20,20 21 bismethylenedioxy 4,6 pregnadiene- 3,1l-dione.,This product is dissolved in benzene, adsorbed on acid Evaporation ofand lal +ll9 (chloroform).

Following the reactionconditions described in paragraphs two and threeabove, and using benzene as the organic solvent and hydrobromic acid inplace of hydro I chloric acid, 17-20,20-2l-bismethylenedioxy-6-methyl-9a- Ifiuoro-l,4-pregn'adiene-'llpt-ol-3-one is obtained from 6- 3,20-dione. I

EXAMPLE 8 I7 20,20 21 bismethylenedioxy 1,4 p regn'izd ie he-11fi-0l-3-0ne Toa suspension of 500 mg. of1,4-pregnadiene-llfll7a,2l-triol-3,20-dione in 25 ml. of chloroform isadded a mixture of 10 ml. of formalin and 10 ml. of concentratedhydrochloric acid. The reaction mixture is stirred vigorously at roomtemperature for one hour and at the end of this time, the chloroformlayer is separated and Washed with a saturated solution of sodiumbicarbonate. It is dried and concentrated under reduced pressure to givea gum which crystallizes upon trituration with boiling methanol. Thisproduct is recrystallized several-times from ethyl acetate to yieldl7-20,20-2l-bismethylene dioxy-1,4-pregnadiene-l l {3-01-3 -one.

EXAMPLE 9 17 20,20 21 bismethylenedioxy 9oz -fluo ro 4'' pie mane-11fl-0l-3-0ne Five grams of 9e-fluorohydrocortisone acetate are'dis- Isolved in 250 ml. of chloroform. To the stirred solution is added 100ml. of concentrated hydrochloric acid'and 100 ml. of 37% aqueousformaldehyde (formalin). After stirring at room temperature for 18hours, the chloroform layer is separated, washed with saturated sodiumbicarbonate, dried and evaporated to dryness. Trituration of the oilwith methanol gives 1.1 grams of l7-20,20 -2lbisrnethylenedioxy 90cfiuoro 4 pregncne 1118 01- 3-one,melting point (245) 248-255 C.

"dissolved in one liter of chloroform and to this stirred solution isadded 400 ml. of concentrated hydrochloric acid and 400 ml. of formalin.The reaction mixture is stirred at room temperature for one hour andworlted up as described in Example 9. "The product "melts at 250-260C.,'285290 C.

EXAMPLE l1 Hydrolysis and acetylation of17-20,20-2l-bismethyiehedi0xy-4-pregnene-3JI-dione t0 corlisone acetateTo mg. of the bismethylenedioxy derivative obtained as in Example 1 isadded 5 ml. of methanol and 5 ml. of 5 N sulfuric acid and theheterogeneous mixture refluxed on the steam bath for one hour(homogeneous after 45 minutes). The methanol is removed in vacuo and theresulting aqueous solution thoroughly extracted with ethyl acetate. Theextract is washed with sodium bicarbonate, dried and concentrated togive 96 mg. of residue. This is dissolved in 0.3 ml. of pyridine and 0.3ml. of acetic anhydride. The mixtureis heated for ten minutes on thesteam bath and poured into Water. The resultant mixture is extractedseveral times with methylene chloride, the methylene chloride washedwith dilute hydrochloric acid and sodium bicarbonate, dried overmagnesium sulfate and evaporated. The residue is recrystallized fromacetone to give cortisone acetate.

EXAMPLE l2 1 7-20,20-21 -bismethylenedioxy- -pregnene-lfi-ol-3 orteseparated, the aqueous layer extracted with chloroform and the solutioncombined. They are washed With sodium bisulfate, dried and concentratedin vacuo. .The entire residue is chromatographed on acid Washed'alu-Elution of the column with 1:4 petroleum ethermina.

. for two hours.

' fate.

17-20,20-21-17ismethylenedioxy-4-pregnene-11fl-0l-3-one EXAMPLE 1417-20,20-21 bismethylenedioxy-9u-chloro4-pregnene-1113- l-3-0ne Tengrams of 9,11fi-oxido-4-pregnen-17a-21-diol-3,20- dione are suspended in500 ml. of methylene chloride and to this mixture is added 20 ml. ofhydrochloric acid and 20 ml. of formalin. The reaction is stirred atroom temperature for 90 minutes. Isolation of the reaction product asdescribed above yields seven grams of 17-20,20-21bismethylenedioxy-9a-chloro-4-pregnene-l1B o1 3 one, melting point180-190" C. Recrystallization from methylene chloride-methanol givespure material, melting point 220230 C.

EXAMPLE 15 i 7 -20,2 0-21 bismethylenedioxy-1-pregnene-3,1 1 -dione Amixture of four grams of 1-pregnen-17 0:,21-di0l- 3,11,20-trione, 200ml. of chloroform, 80 ml. of concentrated hydrochloric acid and 80 ml.of formalin is stirred vigorously at room temperature for 48 hours. Atthe end of this time the chloroform layer is separated and washed withthree small portions of 5% potassium carbonate and then with water untilthe Water washings are neutral.

The chloroform solution is dried over magnesium sulfateand the solventremoved in vacuo. There is obtained a light yellow oily solid. Oncrystallization of this material from acetone and recrystallization frommethylene chloride-methanol substantially pure 17-20,20-21bismethylenedioxy 1 pregnene-3,ll-dione, melting point 230-233 C., isobtained.

EXAMPLE 16 17-20,20-21 bismethylenedioxy-allopregnane-11fi-ol- To asolution of 7.1 grams of allopregnane-ll;8,17a,2ltriol-3,20-dione in 350ml. of chloroform is added 140 ml. of cold concentrated hydrochloricacid and 140 ml. of cold neutral formalin. The two-phase mixture isstirred The solvent layers are separated and the' aqueous phaseextracted with two 100 ml. portions 'of chloroform. The chloroformsolutions are combined, washed successively with water, 5% sodiumbicarbonate and water, and then dried over anhydrous magnesiumsulone-ll-methoxymethylether; further elution with ethyl ether givesl7-20,20-21 bismethylenedioxy-allopregnane- -ll}8-ol-3-one, meltingpoint 220-225 C., after recrystallization from ether.

Following the procedure set forth in the above para- The chloroform isthen removed in vacuo and the graph and starting with 6.5 grams of9a-fluoro-L4-pregnadiene-l1;8,l7a,2l-triol-3,20-dione there is obtained17-20,20-21 bismethylenedioxy-9tat-fluoro-1,4-pregnadiene- 1 1,8-01-3-one.

EXAMPLE 17 17-20,20-21 bismethylenedioxy- I-pregnan-3-dne 500 mg. of4-pregnen-17u,21-diol-3,20-dione in 25 ml. of chloroform is added to amixture of 10 ml. of concentrated hydrochloric acid and 10 ml. offormalin. The

resulting two-phase system is stirred at room temperature for 44 hours.At the end of which time the phases are separated and the aqueous phaseextracted with two 25 ml. portions of chloroform. The chloroformextracts are combined, washed with aqueous sodium bicarbonate and withwater, dried and finally distilled. The residual solid is washed withpetroleum ether to give 327 mg. of 17-20,20-21bismethylenedioxy-4-pregnen-3-one, melting point 220245 C.Recrystallization from methanol and methylene chloride-ether raises themelting point to 250- 255 C.

In a similar fashion by employing 4,9(11)-pregnadien-17a,21-diol-3,20-dione as the starting material and using sulfuric inplace of hydrochloric acid, there is obtained 17 20,20-21bismethylenedioxy-4,9(11)-pregnadien-3- one, melting point 218222 C.

EXAMPLE 18 17-20,20-21 bismethylenedi0xy-9ot-chlora-4-pregnene-11p-0l-3-0ne One gram of 9a-chloro hydrocortisone acetate in ml. ofmethylene chloride is added to a pre-cooled mixture of 25 ml. ofmethanol free formaldehyde in 25 ml.

of concentrated hydrochloric acid. The reaction mixture EXAMPLE 1917-20,20-21 bismethylenedioxy-9m-bromo-4- pregnene-11fl-0l-3-one To astirred solution of 1.6 grams of 9,11-oxido-4-pregnen-17a,2l-diol,3-20-dione in 100 ml. of chloroform is added a coldmixture of 50 ml. of formaldehyde and 50 ml. of 40-42% hydrobromic acid.The reaction mixture is stirred at room temperature for 4 /2 hours. Atthe end of this time the chloroform layer is separated, washed withwater and sodium bicarbonate solution, and dried. The chloroform is thenremoved in vacuo and the residual oil triturated with methanol. Crystalsof 17- 20,20-21 bismethylenedioxy-9a-bromo-4-pregnene-llB-ol- 3-one areobtained which, after recrystallization from methanolmethylene chloride,melts at -177 C.

Oxidation of this substance with pyridine-chromium trioxide complexyields 17-20,20-21 bismethylenedioxy- 9a-bromo-4-pregnene-3, 1 l-dione.

EXAMPLE 20 17-20,20-21 bismethylenedioxy-I6u-methyl-4- pregnene-3,1 I-dione ring 237 ml. of 37% hydrochloric acid and 237 ml. of 37%formaldehyde. This mixture is stirred at room temperature for 70 hours.The chloroform layer is then sep 11B-ol-3-one, melting point 275279 C.that the reaction medium employed in making this substance besubstantially methanol-free.

assess? ares are the 'jaqueeus layer xuaetea twice with "50 m1. ofchloroform. The chloroform solution and extracts'are combined, washedwith saturated sodium bicarbonate solution and with Water. Thechloroform solution is then dried over magnesium sulfate andconcentrated in vacuo until crystallization occurs. The resulting slurryis flushed with 100 ml. of methanol to remove the chloroform and thendissolved in approximately 200 ml. of methanol. The methanol solution isconcentrated in vacuo to a volume of about 75 ml. and cooled to 5 C. Theslurry is filtered and the crystalline material washed with coldmethanol to give 17-20,20-21bismethylenedioxy-loamethyl-4-pregnene-3,ll-dione, melting point 231236C.

The same product is obtained when sulfurous acid is used-in place ofhydrochloric acid as the acid catalyst.

EXAMPLE 21 17 20,20-2 1 Eisinethylenedi0xy-16m-methyl-4- pi-eghene-I 1fi-0l-3-one A mixture of 47.5 ml. of formaldehyde (low in meth- -anolcontent) and 47.5 ml. of concentrated hydrochloric acid are added at 0'C. to a solution of 5 grams of 16amethyl hydrocortisone in 182 ml. ofmethanol-free chloroform. The mixture is stirred at room temperature ina nitrogen atmosphere for 24 hours. The chloroform layer is thenseparated and the aqueous layer extracted with chloroform. Thechloroform solutions are combined, washed with two 50 ml. portions ofwater, sodium bicarbonate solution and water. The chloroform solution isthen dried over magnesiurn sulfate, filtered and concentrated todryness. The residue is triturated with "cold methanol and the crudesolid thus obtained is dissolved in 215 ml. of benzene andchromatographed on 400 mg. of Florosil, elution with acetone in nhexaneand concentration of these fractions yields 17- 20,20-21bismethylenedioxy-16a-methyl-4-pregnene-11,8-

ol-3-one, melting 278283 C.

The llfl-methoxy methyl ether of said substance is obtained on elutionof the column with 7% acetone in n-hexane, melting point 240-243 C.after recrystallization from chloroform-hexane.

' EXAMPLE 22 conditions of Example 7 hereinabove there is obtained 17-20,20-2l bismethylenedioxy-6u methyl-4 pregn'ene- It is importantEXAMPLE 23 1 7-2 0,20-21 bismethylenediaxy-I 6 B-methyl-4-pregnene- 3 ,11 -di0ne temperature for 20 hours, followed by addition of 960 ml. ofWater. The layers are separated and-the aqueous layer extracted withthree 200 ml. portions of methylene chloride. The combined methylenechloride layer and extracts are washed with 200 ml, of water and excesspotassium bicarbonate, and two 200 ml. portions of 'waterytney are driedover magnesinum sulfate and taken to dryness in vacuo (fiush'ed'twicewith benzene). The residue is triturated with ether 'to yield 6.69 gramsof crystalline 17-20,20-21 bismethylenedioxy-l6B-methyl-4-pregnene-3,11-dione, melting point 220-247 C. (dec.).

The starting material for making this material is prepared as follows:

To a solution of 3a-acetoxy-l6-pregnene-11,20-dione in a mixture oftetrahydrofuran and ethyl ether is added diazomethane to produce3a-acetoxy-16or,'17ot-methyleneazopregnane-11,20-dione (melting point186190 C.) which precipitated from solution. Heating this compound atabout 180 C. in vacuo produces 3ct-acetoxy-l6-methyl-16-pregnene-ll,20-dione (melting point 165167 C.) which upon reactionwith hydrogen peroxide in the presence of sodium hydroxide in methanolsolution for :18 hours at room temperature affords16a,17a-epoxy-3ahydroxy-16,9-methyl-pregnane-l1,20-dione (melting point178-180 C.). When this compound is treated with perchloric acid inaqueous dioxane at 2530 C. for 65 hours and the resulting reactionmixture is diluted with water a mixture of3a,17a-dihydroxy-l6-rnethyl-15- pregnene-11,20-dione and3a,17oc-dihydr0xy-l6-methylene-pregnane (melting point 158167 C.) isprecipitated and recovered by filtration. Reduction of this mixture withhydrogenin methanol in the presence of palladiumcalcium carbonatecatalyst affords a mixture of 3a,17a dihydrox-16x-methylpregnane-11,20-dione and30:,17adihydroxy-l6B-methylpregnane-11,20-dione sintering at C.Bromination of this mixture with bromine in chloroform at 4045 C.affords a mixture of 2l-bromo- 3a,17a dihydrox-16a-methylpregnane-11,20-dione and 21bromo-3a,17u-dihydroxy-16,8-methylpregnane-l1,20- dione which uponreaction with potassium acetate and potassium iodide in acetone producesa mixture of 3a,17a,21-trihydroxy-lGti-methylpregnane-l1,20-dione 21-acetate and 3a,l7a,2l-trihydroxy-loa-methylpregnane- 11,20-dione21-acetate. To a solution of this mixture in aqueous t-butanol at 10--15C. is added N-bromosuccinimide to produce a mixture of17a,21-dihydroxy-16umethylpregnane-3,l1,20-trione 21-acetate and17a,2l-dihydroxy 16p methylpregnane-3,11,20-trione 2 l-acetatc which onchromatography on neutral alumina and elution with chloroform-benzene(1:1) and benzene yields17a,2l-dihydroxy-16/9-methylpregnane-3,11-20-trione 21- acetate (meltingpoint 2l02l3 C.). Reaction of this compound with bromine in a mixture ofacetic acid and chloroform affords the corresponding 4-bromo compound(melting point -170" C. dec.) which is converted by reaction withsemicarbazide to the 3-semicarbazone of 17a,21-dihydroxy 16Bmethyl-4-pregnene-3,11,20-trione 21-acetate. Treatment of this compoundwith a mixture of acetic acid and pyruvic acid gives1706,21-dil'lYdl'OXY- 16B-methyl-4-pregnene-3,11,20-trione 21-acetate(melting point 226-232 C.). This latter substance is then hydrolyzed tothe C-21 free alcohol by treatment with potassium bicarbonate orpotassium hydroxide in aqueous methanol.

EXAMPLE 24 17-20,20-21bismethylenedioxy-I6B-methyl-3-ethylenedioxy-5-pregnen-1 1 -one 17.5grams of 17-20,20-21 bismethylenedioxy-lfi/S- methyl cortisone (preparedas in Example 23) is dissolved in 890 ml. of benzene, 45 ml. of ethyleneglycol and 1.78 grams of p-toluene sulfonic acid, and the mixture heatedat reflux for 17.5 hours. During this time a water separator is used toremove the water as it distills. The reaction mixture is then cooled to20 C., washed with two 200 cc. portions of water, 200 cc. of saturatedsodium bicarbonate solution and 200 cc. of Water, The organic layer isdried over anhydrous magnesium sulfate and concentrated to a solid. Thesolid after trituration with ether yields 12.4 grams of 17-20,20-2lbismethylenedioxy-l 6B-methyl-3-ethylenedioxy-5 -pregr1en-1 l-one.

13 EXAMPLE 2s 17-20,20-21 bismethylenedioxy-1 6fl-methyl-L4-pregnadime-3,1 1 dione with three 25 ml. portions of methylenechloride. The

combined methylene chloride ,layer and extracts are washed with 35 ml.of aqueous potassium bicarbonate" and three ml. portions of water, driedover anhydrous magnesium sulfate and concentrated to dryness in vacuo.The residue is flushed with benzene, during which process itcrystallized. The yield of crystalline -17-20,20-21 bismethylenedioxy1613 methyl 1,4 pregnadiene-' 3,11-dione is 1.28 grams.

The 16,8 methyl 1,4 pregnadien 17a,21 diol- 3,11,20-trione is preparedby treating 16,8-methyl-4- pregnen-'17a ,21-diol-3,11,20-trione21-acetate with selenium dioxide in t-amyl alcohol, and then saponifyingthe ZI-acetate ester by warming in methanolic potassium bicarbonate.

EXAMPLE 26 17-20,20-21 bismethylenedioxy9a-fluor0-4-pregnene-3,1 1-

dione When 9a-fll10l'0 cortisone is treated according to the procedureset forth in Example 18, using sulfuric acid in place of hydrochloricacid, there is obtained 17-20, 20-21bismethylenedioxy-9a-fluoro-4-pregnene-3,1 l-dione, melting point275-290 C,

EXAMPLE 27 17 20,20 21 bismethylenedioxy 3 pyrrolidyl 3,5- pregnadien-I1 one 500 mg. of 17-20,20-21 bismethylenedioxy-4-pregnene- 3,11-dione isdissolved in about 10 ml. of ethanol containing a little methylenechloride. This is concentrated to about 5 ml. to remove methylenechloride. To the concentrate is added 0.5 ml. of pyrrolidine and themixture heated for one minute on the steam bath. The resultantprecipitate is cooled and filtered, and washed with ethanol to give 540mg. of light yellow prisms, melting point 205- 212 C. (dec.), of17-20,20-21 bismethylene-dioxy-3- pyrrolidyl-3,S-pregnadien-l l-one.

Any departure from the above description which conforms to the presentinvention is intended to be included within the scope of the claims.

What is claimed is:

1. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position asubstituent selected from the class consisting of keto and hydroxygroups and groups convertible thereto by hydrolysis, and having at thell-position a substituent selected from the class consisting ofhydrogen, hydroxy and keto groups; and unsaturated derivatives thereof.

2. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position asubstituent selected from the class consisting of keto and hydroxygroups and groups convertible thereto by hydrolysis, having at the9-position a substituent selected from the class consisting of halo andhydroxy groups, and having at the ll-position a substituent selectedfrom the class consisting of hydroxy and keto groups; and unsaturatedderivatives thereof.

3. 17-20,20-21 bismethylenedioxy pregnanes having at the 3-position asubstituent selected from the class consisting of keto and hydroxygroups and groups convertible thereto by hydrolysis, having at the9-position a substituent selected from the class consisting of hydrogen,.halo and hydroxy groups and at the ll-position', a

substituent selected from the class consisting of hydrogen, 4

hydroxy and keto groups and having at the 16-position a lower alkylgroup; and unsaturated derivatives thereof having atleast one ring Adouble bond.

4. 17-20,20-21 bismethylenedioxy pregnanes having an oxygenated functionat the 3-position; and nuclearly unsaturated derivatives thereof.

5. 17-20,20-21 bismethylenedioxy 4 pregnene 3,11- dione.

6. 17-20,20-21 bismethylenedioxy 4 pregnene-llp-ol- 3-one.

7. 17-20,20-21 bismethylenedioxy 1,4 pregnadiene-3, ll-dione.

8. 17-20,20-21 bismethylenedioxy-1,4-pregnadiene-11pol-3-one.

9. 17-20,20-21 bismethylenedioxy-9a-fluoro-4-pregnene- 11fi-ol3-one.

10. 17-20,20-21 bismethylenedioxy-9a-fluoro-1,4-pregnadiene-l1/8-ol-3-one.

11. 17-2o,20-21 bismethylenedioxy-16-rnethyl-4-pregnene-3,1 l-dione.

12. 17-20,20-21 bismethylenedioxy-16e-methy1-4-prcgnene-11B-ol-3-one.

13. 17-20,20-21 bismethylenedioxy-16-methyl-1,4-pregnadiene-l 1 13-01-3one.

14. l7-20,20-2lbismethylenedioxy-9oc-fluoro-16-rnethyl-l,4-pregnadiene-1 1,8-ol-3-one.

15. 17 -20,20-21 bismethylenedioxy 16p methyl-1,4- pregnadiene-3,ll-dione.

16. The process for preparing a 17-20,20-21 bismethylenedioxy steroidthat comprises reacting a member of the class consisting of3-oxygenated-17a,21-dihydroxy- 20-keto pregnanes and unsaturatedderivatives thereof with formaldehyde in the presence of an acidselected from the class consisting of acids having a --log k of lessthan 2.25 and formic acid.

17. The process of claim 16 wherein the acid is a mineral acid.

18. The process for preparing a 17-20,20-21 bismethylenedioxy steroidthat comprises reacting a member of the class consisting of3,11-bisoxygenated-17u,2l-dihydroxy-ZO-keto pregnanes and unsaturatedderivatives thereof with formaldehyde in the presence of an acidselected from the class consisting of acids having a log k of less than2.25 and formic acid.

19. The process for preparing a 17-20,20-21 bimethylenedioxy steroidthat comprises reacting a member of the class consisting of16-rnethyl-3,1l-bisoxygenated-Ua, 2l-dihydroxy-20-keto pregnanes andunsaturated derivatives thereof with formaldehyde in the presence of anacid selected from the class consisting of acids having a log k of lessthan 2.25 and formic acid.

20. The process which comprises reacting 4-pregnen-17a,21-diol-3,l1,20-trione with formaldehyde in the presence of an acidselected from the class consisting of acids having a log k of less than2.25 and formic acid to produce 17-20,20-21bismethylenedioxy-4-pregnene-3, ll-dione.

21. The process which comprises reacting 4-pregnen-17a,2l-diol-3,l1,20-trione with formaldehyde in the presence ofhydrochloric acid in an aqueouszorganic solvent two-phase reactionmedium to produce 17-20,20-21 bismethylenedioxy-4-pregncue-3, 1 l-dione.

22. The process which comprises reacting1,4-pregnadien-17a,21-diol-3,l1,20-trione with formaldehyde in thepresence of an acid selected from the class consisting of acids having alog k of less than 2.25 and formic acid to produce 17-20,20-21bismethylenedioxy-1,4-pregnadiene-3,1 l-dione.

23. The process which comprises reacting1,4-pregnadiene-llfl,l7a,21-triol-3,20-dione with formaldehyde in thepresence of an acid selected from the class consisting of acids having alog k of less than 2.25 and formic assess? :"acld'to produce 17-20;20?21.bismethylenedioxy-l,4-preg- 'nadiene-l'lfi-ol-B-one.

24. The process which comprises reacting 9u-fiuor0-4-"pregnene-l1,8,17a,21-triol-3,20-dione with formaldehyde in the presenceof an acid selected from the class consisting of acids having a -log kof less than 2.25 and formic acid to produce 17-20,20-21bismethylenedioxy- 9a-fluoro-4-pregnene-l 1 B-ol-S-one.

25. The process which comprises reacting 16-rnethyl- 4 pregnen 17,2ldiol 3,11,20 trione With form- 'aldehyde in the presence of an acidselected from the class consisting of acids having a log k of less than2.25 and formic acid to produce 17-20,20-21 'oisrnethylenedioxy 16methyl 4 pregnene 3,11 dione.

26. The process which comprises reacting 16-n1ethyl- 4-pregnen l7zx,21diol 3,11,20 trione With formaldehyde in the presence of hydrochloricacid in an vaqueonsmrganic solvent two-phase reaction medium to formicacid to produce 17-20,20-21 bismethylenedioxy- 16a-methyl-4-pregnene-1 161-01-3 -one.

28. The process which comprises reacting 16-methyl- 1 I i F Au 1,4pregnadiene 11fl,l7a,21 triol 3,20 dione with formaldehyde in thepresence of an acid selected from the class consisting of acids having alog k of less than 2.25 and formic acidto produce 17-20,20-21bismethylenedioxy-16-methyl-1,4-pregnadiene 11fi-ol-3-one.

29. The process which comprises reacting 9oz-fill0l'0- 16 methyl 1,4pregnadiene 1l}8,17oz,21 triol 3,20- dione with formaldehyde in thepresence of an acid selected from the class consisting of acids having alog k of less than 2.25 and formic acid to produce 17-20,20-21bismethylenedioxy 9a fluoro .1 6 methyl 1,4 pregnadiene-11fl-ol-3-one.

30. The process which comprises reacting 9a-fluoro-16- methyl 1,4pregnadiene 11/3,17a,21 triol 3,20- dione with formaldehyde in thepresence of hydrochloric acid in an aqueousmrganic solvent two-phasereaction medium to produce 17-20,2()- 21 bisrnethylenedioxy-9afluoro 16methyl 1,4 pregnadiene 11B ol 3 one.

31. The process which comprises reacting 16fi-methyl- 1.4 pregnadien 170,21 triol 3,11,20 t rione with formaldehyde in the presence ofan acidselected from the class consisting of acids having a log k of lessthan2.25 and formic acid to produce 17 20,20-21bismethylenedioxy-l65-methy1-1,4-pregnadiene-3,1 l-dione.

No references cited.

1. 17-20,20-21 BISMETHYLENEDIOXY PREGANANES HAVING AT THE 3-POSITION ASUBSTITUENT SELECTED FROM THE CLASS CONSISTING OF KETO AND HYDROXYGROUPS AND GROUPS CONVERTIBLE THERETO BY HYDROLYSIS, AND HAVING AT THE11-POSITION A SUBSTITUENT SELECTED FROM THE CLASS CONSISTING OFHYDROGEN, HYDROXY AND KETO GROUPS; AND UNSATURATED DERIVATIVES THEREOF.